Printed circuit board and method for manufacturing the same

ABSTRACT

A method for manufacturing a printed circuit board (PCB) with high component density includes at least two reinforcing plates, at least two connecting plates, a first circuit board unit, and a second circuit board unit. The reinforcing plate includes a supporting portion, a first connecting portion, and a second connecting portion. The first connecting portion and the second connecting portion connect to ends of the supporting portion. The connecting plates are bendable circuit boards. Each connecting plate is attached to the supporting portion, the first connecting portion, and the second connecting portion of a reinforcing plate. The first circuit board unit is fixed and electrically connected to a connecting plate away from first connecting portion. The second circuit board unit is fixed and electrically connected to a connecting plate away from the second connecting portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

The subject matter herein generally relates to electronic cigarettes.This application is a divisional application of U.S. patent applicationSer. No. 16/243,397, filed on Jan. 9, 2019, which claims priority to CNPatent Application with Serial Number 201811243821.2, filed on Oct. 24,2018, the disclosure of which is incorporated herein by reference.

FIELD

The subject matter herein generally relates to a printed circuit board(PCB) and a method for manufacturing the PCB.

BACKGROUND

Electronic elements are mounted on PCBs. In order to increase populationelement density, one PCB is superimposed on another PCB and a connectoris disposed between the two opposite PCBs to provide greater area.

The connector generally includes an interposer. The interposer ishollowed out to provide space for the electronic elements on the twoopposite PCBs. Edge of the interposer defines through holes bymechanical drilling. Inner surfaces of the through holes are plated withmetal to connect the two opposite PCBs.

The above described circuit board manufacturing method is complicated.Therefore, there is room for improvement within the art.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations of the present technology will now be described, by wayof embodiments, with reference to the attached figures.

FIG. 1 is a schematic view of a PCB according to an embodiment.

FIG. 2a is a cross-sectional view of a connecting plate of the PCB inFIG. 1.

FIG. 2b is a top view of the connecting plate of the PCB in FIG. 1.

FIG. 3 is a flow chart of a method of manufacturing a PCB.

FIG. 4 is a cross-sectional view of a copper clad unit.

FIG. 5 is a cross-sectional view of the copper clad unit of FIG. 4 withlines.

FIG. 6 is a cross-sectional view of the copper clad unit of FIG. 5 witha cover layer.

DETAILED DESCRIPTION

It will be appreciated that for simplicity and clarity of illustration,where appropriate, reference numerals have been repeated among thedifferent figures to indicate corresponding or analogous elements. Inaddition, numerous specific details are set forth in order to provide athorough understanding of the embodiments described herein. However, itwill be understood by those of ordinary skill in the art that theembodiments described herein can be practiced without these specificdetails. In other instances, methods, procedures, and components havenot been described in detail so as not to obscure the related relevantfeature being described. Also, the description is not to be consideredas limiting the scope of the embodiments described herein. The drawingsare not necessarily to scale and the proportions of certain parts may beexaggerated to better illustrate details and features of the presentdisclosure.

The disclosure is illustrated by way of example and not by way oflimitation in the figures of the accompanying drawings, in which likereferences indicate similar elements. It should be noted that referencesto “an” or “one” embodiment in this disclosure are not necessarily tothe same embodiment, and such references mean “at least one.”

The term “comprising,” when utilized, means “including, but notnecessarily limited to”; it specifically indicates open-ended inclusionor membership in the so-described combination, group, series, and thelike.

Referring to FIG. 1, a PCB 100 is provided. The PCB 100 includes atleast two reinforcing plates 10, at least two connecting plates 20, afirst circuit board unit 30, and a second circuit board unit 40. Thereinforcing plate 10 includes a supporting portion 11, a firstconnecting portion 12, and a second connecting portion 13. The firstconnecting portion 12 and the second connecting portion 13 are connectedat opposite ends of the supporting portion 11. The at least twoconnecting plates 20 are bendable flexible circuit boards. Each of theconnecting plates 20 is attached to the supporting portion 11, the firstconnecting portion 12 and the second connecting portion 13 of one of theat least two reinforcing plates 10. The first circuit board unit 30 isfixed and electrically connected to a side of each of the connectingplates 20 away from the first connecting portion 12. The second circuitboard unit 40 is fixed and electrically connected to a side of each ofthe connecting plates 20 away from the second connecting portion 13.

In the embodiment, the PCB 100 includes two reinforcing plates 10. Thetwo reinforcing plates 10 are oppositely disposed between the firstcircuit board unit 30 and the second circuit board unit 40. In anotherembodiments, the PCB 100 includes four reinforcing plates 10. The fourreinforcing plates 10 are disposed around edge of four sides of thefirst circuit board unit 30 and the second circuit board unit 40. It canbe understood that the number and the positions of the reinforcingplates 10 can be set as needed as long as the first circuit board unit30 and the second circuit board unit 40 have sufficient space.

The reinforcing plate 10 is substantially in a shape of a “⊏”. In theembodiment, an angle between the first connecting portion 12 or thesecond connecting portion 13 and the supporting portion 11 is 90°±5°. Aheight of the reinforcing plate 10 is greater than or equal to a sum ofa height of elements on the first circuit board unit 30 and a height ofelements on the second circuit board unit 40. A width of the firstconnecting portion 12 is greater than or equal to a width of aconnecting region of the connecting plate 20 and the first circuit boardunit 30. A width of the second connecting portion 13 is greater than orequal to a width of the connecting region of the connecting plate 20 andthe second circuit board unit 40.

In at least one embodiment, the reinforcing plate 10 is made ofconductive material, such as stainless steel, copper, etc. Thereinforcing plate 10 also can be made of insulating material, such asacrylic, liquid crystal polymer or the like. In the embodiment, thereinforcing plate 10 is made of conductive material.

Referring to FIG. 2a and FIG. 2b , the connecting plate 20 includes abase layer 21, a wiring layer 22, and a cover layer 25. The cover layer25 includes an adhesive layer 23 and a base film 24. A first side of thewiring layer 22 is attached to the base film 24 through the adhesivelayer 23. A second side opposite to the first side of the wiring layer22 is pressed against the base layer 21. The cover layer 25 defines awindow 251 to expose portions of the wiring layer 22 near edges of thewiring layer 22, to be connected to the first circuit board unit 30 andthe second circuit board unit 40.

A thickness of the wiring layer 22 is designed in accordance with acopper thickness specification of a circuit-manufacturing process. Thethickness of the wiring layer 22 is less than or equal to 3 μm. Thewiring layer 22 is applied with line patterning and surface treatment toform a line pattern 26, and the base film 24 is pressed by the adhesivelayer 23 onto the wiring layer 22 to cover the line pattern 26. Two endsof the line pattern 26 are partly exposed through the window 251 to forman exposed portion 261. The exposed portion 261 of the line pattern 26is surface-treated to form a protection layer 27. The protection layer27 is electrically conductive with the line pattern 26.

The material of the base layer 21 and the base film 24 may be selectedfrom, but are not limited to, polyimide (PI), liquid crystal polymer(LCP), and polyethylene terephthalate (Polyethylene), terephthalate,PET), and one of polyethylene naphthalate (PEN).

The adhesive layer 23 can be made of, but is not limited to, polyimide,liquid crystal polymer, polyethylene terephthalate, and polyethylenenaphthalate.

The adhesive layer 23 can be made of viscous resin selected from a groupconsisting of polypropylene, epoxy resin, polyurethane, phenolic resin,urea-formaldehyde resin, melamine-formaldehyde resin, and polyimide.

The PCB 100 supports the first circuit board unit 30 and the secondcircuit board unit 40 by the reinforcing board 10. The connecting plate20 is fixed to the reinforcing plate 10 and electrically connects thefirst circuit board unit 30 and the second circuit board unit 40. Thethickness and the size of the reinforcing plate 10 can be adjusted asneeded to reduce space. Because the process is simple, the cost can bemaintained low.

Referring to FIG. 3, a method for making a PCB 100 is presented. Themethod for making the PCB 100 is provided by way of embodiments, asthere are a variety of ways to carry out the method. The method canbegin at block 101.

At block 101, at least two connecting plates are provided. The at leasttwo connecting plates are bendable flexible circuit boards.

At block 102, at least two reinforcing plates are provided. Each of thereinforcing plates includes a supporting portion, a first connectingportion, and a second connecting portion. The first connecting portionand the second connecting portion are connected to opposite ends of thesupporting portion.

At block 103, the at least two connecting plates are bent and each ofthe connecting plates is attached to the supporting portion, the firstconnecting portion, and the second connecting portion of one of the atleast two reinforcing plates.

At block 104, a first circuit board unit is provided, and the firstcircuit board unit is fixed and electrically connected to a portionwhere each of the connecting plates is attached to the first connectingportion.

At block 105, a second circuit board unit is provided, and the secondcircuit board unit is fixed and electrically connected to a portionwhere each of the connecting plates is attached to the second connectingportion.

Referring to FIG. 2a and FIG. 2b , in the embodiment, at block 101, twoconnecting plates 20 are provided and the two connecting plates 20 arebendable flexible circuit boards.

Referring to FIGS. 4-6 and 2 a, a process for making a connecting plate20 comprises:

Referring to FIG. 4, a copper clad unit 201 is provided. The copper cladunit 201 includes a base layer 21 and a copper foil layer 210.

Referring to FIG. 5, line patterning is applied to the copper foil layer210 to form a line pattern 26, thereby obtaining a wiring layer 22.

Referring to FIG. 6, a cover layer 25 is disposed on the wiring layer 22to cover the line pattern 26. The cover layer 25 defines a window 251. Aportion of the line pattern 26 exposed by the window 251 forms anexposed portion 261. The window 251 is formed by cutting operation,laser, or the like.

Referring to FIG. 2a , surface treatment is applied to the exposedportion 261 of the line pattern 26 for electrical connections to anexternal structure.

FIG. 4 is a cross-sectional view of the copper clad unit 201. The copperclad unit 201 is made of an FPC raw material board, which is asingle-sided copper-clad board.

FIG. 5 is a cross-sectional view of the copper clad unit 201 with lines.The line pattern 26 is formed by development, etching, and film removal.

FIG. 6 is a cross-sectional view of the copper clad unit 20 attached tothe cover layer 25. The cover layer 25 includes the adhesive layer 23and base film 24. The base film 24 is pressed against the wiring layer22 by the adhesive layer 23 to cover the line pattern 26. A part of theline pattern 26 is exposed by the window 251.

Referring also to FIG. 2a , the surface treatment of the exposed portion261 of the line pattern 26 may be applied by electroless nickelimmersion, gold plating, oxidation prevention, electroless palladiumimmersion, or the like to form the protection layer 27 on the surface ofthe exposed portion 261 of the line pattern 26. The protection layer 27and the line pattern 26 are electrically conductive.

Referring to FIG. 1, in the embodiment, at block 102, the tworeinforcing plates 10 are provided. Each of the reinforcing plates 10includes a supporting portion 11, a first connecting portion 12, and asecond connecting portion 13. The first connecting portion 12 and thesecond connecting portion 13 are connected to opposite ends of thesupporting portion 11.

At block 103, the at least two connecting plates 20 are bent and each ofthe connecting plates 20 is attached to the supporting portion 11, thefirst connecting portion 12, and the second connecting portion 13 of oneof the at least two reinforcing plates 10.

The connecting plate 20 is adhered to the reinforcing plate 10 by a gluelayer. The exposed portions 261 are located near the first connectingportion 12 and the second connecting portion 13.

At block 104, the first circuit board unit 30 is provided. The firstcircuit board unit 30 is fixed and electrically connected to a portionwhere each of the connecting plates 20 is attached to the firstconnecting portion 12.

Referring to FIG. 1 and FIG. 6, the first circuit board unit 30 iselectrically connected to the exposed portion 261 of the connectionboard 20 by a conductive material 28 such as solder paste or anisotropicconductive adhesive or the like.

At block 105, the second circuit board unit 40 is provided. The secondcircuit board unit 40 is fixed and electrically connected to a portionwhere each of the connecting plates 20 is attached to the secondconnecting portion 13.

The second circuit board unit 40 is disposed opposite to the firstcircuit board unit 30. The second circuit board unit 40 is electricallyconnected to the exposed portion 261 of the connection board 20 bysolder paste or an anisotropic conductive adhesive or the like.

Even though information and advantages of the present embodiments havebeen set forth in the foregoing description, together with details ofthe structures and functions of the present embodiments, the disclosureis illustrative only. Changes may be made in detail, especially inmatters of shape, size, and arrangement of parts within the principlesof the present embodiments to the full extent indicated by the plainmeaning of the terms in which the appended claims are expressed.

What is claimed is:
 1. A method for manufacturing a printed circuit board comprising: providing at least two reinforcing plates, each of the reinforcing plates comprising a supporting portion, a first connecting portion and a second connecting portion, the first connecting portion and the second connecting portion connected to two ends of the supporting portion to form a shape of a “⊏” reinforcing plate; and attaching each of at least two connecting plates to the supporting portion, the first connecting portion and the second connecting portion of one of the two reinforcing plates; fixing and electrically connecting a first circuit board unit to a side of each of the two connecting plates away from first connecting portion; and fixing and electrically connecting a second circuit board unit to a side of each of the two connecting plates away from the second connecting portion.
 2. The method of claim 1, wherein the first circuit board unit is electrically connected to the connection plates by solder paste.
 3. The method of claim 1, wherein the first circuit board unit is electrically connected to the connection plates by anisotropic conductive adhesive.
 4. The method of claim 1 further comprising making the at least two connecting plates comprising: providing a copper clad unit comprising a base layer and a copper foil layer; depositing a wiring layer on the copper foil layer by patterning lines on the copper foil layer to form a line pattern; disposing a cover layer disposed on the wiring layer to cover the line pattern, wherein an opening is defined in the cover layer to expose a portion of two ends of the line pattern to form an exposed portion; and surface treating on the exposed portion so that the exposed portion is electrically connectable to an external structure.
 5. The method of claim 4, wherein the exposed portion is surface treated by electroless nickel immersion gold, oxidation prevention or electroless nickel electroless palladium immersion gold.
 6. The method of claim 1, wherein each of the connecting plates is a bendable flexible circuit board.
 7. The method of claim 1, wherein an angle between the first connecting portion and the supporting portion is between 85° and 95°.
 8. The method of claim 1, wherein an angle between the second connecting portion and the supporting portion is between 85° and 95°.
 9. The method of claim 1, wherein the reinforcing plates are made of conductive material. 